Using models and slowing down footage.

Discussion in 'Fan Films, Fan Audio & SciFi 3D' started by PixelMagic, Mar 29, 2002.

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  1. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Ok, guys, I have a question. In TSDM we are trying to make a scene in which a X-Wing crashes into a forest. Unfortuatly, this is very hard to accomplish in computer graphics. SO, I am going back the traditional route by using a scale model of an X-wing. Now, don't start that "Oh, models are very hard to make look convincing" Yes, I know, but I built models since I was 7, so I know how to do it so that they look convincing. Also, the model will be moving by the camera and crashing through a model of railroad trees and it won't really matter. NOW, I have a couple of questions. On my camera is says a "shutter speeds" of 1/60, 1/75, 1/300, and 1/500. I know that still means it will play at 30 fps though. Someone told me I need to do a formula based on the scale of the model to figure out by what percentage to slow the footage down. BUT, I read that you can only slow the footage down by about 30% before it starts to look jerky. Any comments, thoughts?
  2. Chad_Peter Jedi Knight

    Member Since:
    Aug 9, 2000
    star 3
    Shoot that shot on film. Seriously.

    --Chad

  3. DaftMaul Former TFN Fan Films Staff

    VIP
    Member Since:
    Feb 18, 2001
    star 5
    The 1/60th etc is the amount of time your shutter is actual open for 'per frame' (one sixtyth of a second, one five hundredth of a second) so all this will do is either make the images look a little 'motion blurred', or very sharp (you obviously need to light the model very brightly in order to acheive a 1/500th of a second exposure.

    So onto your question, you obviously need to slow down your footage, and since (I guess) you are shooting on video, you are kind of limited on in camera options. Post camera I read somewhere that you can de-interlace your footage, and combine both fields to make the thing look as though it is 'twice as slow' (not sure how exactly) But you can also slow the thing down on your comp. (In after effects this will be frame blending) I remember seeing a clip posted by SJSUAmidala a way back where he slowed a clip of himself down in Final Cut Pro, and the thing looked flawless to me, really impressive. To be fair it was only his face moving around, I'm not sure if you would get the same results trashing a model into a bunch of trees. Either way, I think if you are shooting of dv to need to do all of this in post.
  4. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Chad: Film is not an option

    Daft: So do I leave the shutter speed as it is?

    General: How do I figure out by what percentage to slow the footage down?
  5. Darth_Apporth Force Ghost

    Member Since:
    Nov 29, 2001
    star 1
  6. Darth_Tater Jedi Master

    Member Since:
    Aug 30, 2001
    star 1
    On the FFF there's a guy who did an incredible slow motion effect using a morphing program (freeware, I think, can't remember the name).
    He goes under the name Ziggy Stardust.

    Fan Film Forum
  7. DaftMaul Former TFN Fan Films Staff

    VIP
    Member Since:
    Feb 18, 2001
    star 5
    What you really want to do is make sure you have as large a depth of field as possible (so the entire model is in focus ) With a shallow depth the thing will look really fake. In order to get as big a depth of field as possible you need to shut the iris down to about f22 (assuming your lens can go to f22 - with an f-stop this high/iris so small, you will need to open the shutter for longer in order to 'expose the film' properly, so you'll need a slow shutter speed (this is where your 1/60th will come in)

    If your camera has a few auto/manual features you could try setting the f stop to 22 (or as high as it goes) and see what shutter speed it gives you (automatically) if there isn;t enough light, don't choose a lower f-stop, try adding more lights to your model, becuase (as I said before) if that model goes out of focus afterr a few inches it's the best way to make the thing look fake.
  8. DarthFoole Jedi Master

    Member Since:
    Mar 23, 2001
    star 2
    I'm sorry i don't have any input for pixel, but I was wondering whether premiere used the same method for blending frames that After Effects uses. Also, i've heard that the usual way to deinterlace is to throw out one field and then interpolate. is there any better way to do this? any programs that use a better way?

    back to the topic, Pixel, I can't wait to see this crash. what size of model are you using? are you using pre-made railroad trees or are you constructing them? how are you launching the x-wing at the crash site? guy on a ladder throwing hard?
  9. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Actually, I'm not sure what size the model will be, as I will be going to buy it tomorrow. The larger the better. And yes, parts of the model trees will be pre-made, and some of them will be custom tress as well. For the custom trees, I am using saw dust painted green for the leaves. As far as having the model crash, it will not be a hollow model as most are. I'm going to put some weights in it, probably coins, so that it will travel at high speed down two pieces of fishing wire. The fishing wire will then be digitally removed in the computer.
  10. DarthFoole Jedi Master

    Member Since:
    Mar 23, 2001
    star 2
    I can't belie3ve we're in an area that I have some knowledge about.

    Painted sawdust is kind of a difficult material to work with. any water on it (including water-based glue) will leach out some of the paint (or dye). I would suggest using dyed lichen or shredded foam. These materials keep their color much more readily than sawdust, and they look realistic too.
    The lichen is pliable and a little difficult to glue down, but it has very complicated structure, as a real tree would have, and also has some "give," in the same way that real branches bend and return. Lichen is good for larger scale, when you want to see the details in the tree.
    Shredded foam sounds kind of janky, but it looks great on a tree. big and puffy, it fills out the branches well. It's also available in more colors than the lichen.

    the tree armatures themselves might be tricky. Normally, you can go buy a bunch of bendable plastic or metal tree armatures, but these wouldn't look too great if a model crashed into them. you might want to line the actual impact site with real branches and twigs, so they'll break easily and realistically. Twigs make great looking trees, but i don't use them as i never want my models to break. i use twisted wire, textured and painted. However, since your model will be crashing through the forest, you may want to think about using dry, brittle twigs.

    you can make twig trees very quickly with the shredded foam. just take the twig, and paint PVA (elmer's) glue all over it, and either dip it in the bag of foam or stick clumps to it. let dry at least 2 hours before any kind of handling. These trees will bend and snap more realistically when your x-wing crashes into them.

    hope this gives you an idea or two, but feel free to blow me off if it sounds like too much work.

    Kev
  11. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Wow, Darth Foole, that's an excellent idea! I think I will use real twigs. I never thought about it, but it would be hard to get plastic pieces to break and snap realistically. And I think i will use your idea instead of the saw dust. Now, I have two other problems...

    1. How would I go about recreating the sound effects for such a crash?

    2. How do I get my X-wing model to kick up a lot of dust and dirt when it crashes?
  12. Digital_LlamaCH Jedi Master

    Member Since:
    Jan 30, 2001
    star 4
    Perhaps you could gather a load of dirt and dust, place it at the site of the crash --- Off screen, set up someone ready with a fan, pointing in the same direction as the X Wing had been headed, then simply turn it on and let it blast the dust when the X Wing crashes. Then, of course, pull the fan away to let the dust settle.

    You may want the fan to all ready be on and blowing before aiming it at the crash site.

    Just a thought.

    Chad
  13. DarthFoole Jedi Master

    Member Since:
    Mar 23, 2001
    star 2
    Whee! glad to provide some input for ya! I was thinking about dropping some more info but i wasn't sure how interested you'd be.

    >>>1. How would I go about recreating the sound effects for such a crash?

    I think maybe layering lots of rustling and snapping sounds over actual sound clips of trees falling. maybe scan your TV-guide for a program about logging? maybe just use the sound clip of the USS Enterprise crashing from Star Trek 15 (or 7 or whatever number it was. first contact maybe?)


    >>>2. How do I get my X-wing model to kick up a lot of dust and dirt when it crashes?

    I was thinking about this too. if you mount the trees over a fairly soft sheet of foam rubber and liberally cover it with fine dirt and more dyed-foam "turf," the crash should (may) allow lots of the ground material to bounce up. more than if you used a hard surface. I mean, dirt would be a very soft surface for an x-wing, so you'll want a fairly soft surface for your model. i guess you'll have to have a hard surface under the foam to make sure your model breaks up as planned, but experiment with tossing a rock onto a sheet of foam covered in dirt and see how much is kicked up.

    You may also want to plan for some trees to break (and mount them securely) and some trees to be completely uprooted (and mount them not so securely) just be sure no fake-looking material comes up with the tree "roots."



    more ideas are brewing, just keep asking questions if you'd like more input.

    Kev
  14. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Wow, DarthFoole, you've really got some cool ideas for this! I just hope it looks good in the final shot. I wonder if it will be hard from me to find a model of an X-wing. Not sure if they still manufacture them. I'm sure I can find one at a hobby store though. And I'm betting I should get the largest scale they have in the X-Wing. This is going to be an awesome shot if everything works correctly. I'm still unclear on how the X-wing is going to kick up dust, but I think if it's loosely packed enough, the weight of the model (seeing as how a lot of coins will be packed inside the model) will kick up enough. If not, I can add to the effect with CG particles.
  15. DarthFoole Jedi Master

    Member Since:
    Mar 23, 2001
    star 2
    Are you going to have any shots of the x-wing after it's crashed? you may want to decide first exactly how it will break apart, and break it that way, then re-assemble it.

    definately do a test-run first. maybe even assemble a really cheap model and crash it on a bunch of bare twigs to make sure you've got your angles and dust correct. The more i think about it, the more i think you should use a sheet of foam rubber and lay a bunch of fine dirt and turf on it.

    I can't show you what foam trees look like right now, as i haven't made any, but i just took a few shots of some lichen-covered trees that I made a few weeks ago. this material would be good for large-scale models, as the lichen has very complicated structure, but it is difficult to glue down because it's so springy.

    If this works correctly, you should see the images right here, and be able to link to a higher-res pic of them:

    [image=http://www.gameknave.net/starwars/tfn/TreeLooseCluster.jpg]

    [image=http://www.gameknave.net/starwars/tfn/TreeClose-up.jpg]

    [image=http://www.gameknave.net/starwars/tfn/TreeTightCluster.jpg]

    Smaller-scale shots would probably make the lichen look odd, and you'd need too much of it. so, use this method if you find a really really big model, otherwise, use the foam-on-twigs method. or experiment and use what looks good.
  16. malducin Jedi Master

    Member Since:
    Oct 23, 2001
    star 4
    As far as the dirt and dust there are several alternatives. One thing they mention in documentaries is that they use fullers earth which is finer than regular dirt. I've heard also of ground nut shells, but that might be too much nuts and grinding.

    On way would be to have a large area covered with fullers earth and have the model crash into it. For added realism you could put tubes under the dirt and blow some earth up as the model passes for more explosive character.

    The other one would be to film the dust pickup in fromt of a black screen and then composite it over. Actually related you could have the fullers earth in a black screen and some object also black crash into the earth and carve a trough. Then you can key it out and just composite the model over it. Probably need to run some tests to see what fits best.

    As far as shooting speed, video cameras won't help since most shhot at 30 frames per second. There is a formula in one of the ILM book but I wouldn't be able to post it until Monday.
  17. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Humm, I've always thought that lichen didn't look too real. I might use Woodland Scenic leaves. Maybe I should pick up a book on building realistic trees. Also, all of the scale model shots will be enhanced with CG dust, leaves falling, CG branchces breaking, etc. And yes, there will be a shot of the X-Wing model after the crash, just lying there in flames. Sense I am the person in the X-Wing during the crash, I will be greenscreened into the shot walking away from the wreckage.
  18. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Hey, I also like that idea about compositing the dust into the shot. BUT, if the dirt is a reddish-brown color, wouldn't that be hard to key out using black? I could use greenscreen maybe?
  19. DRProducer Jedi Knight

    Member Since:
    Mar 23, 2002
    star 1
    No,I would use a bluescreen for that(the dust I mean.What software are you using for the keying?

    I would try to actually make that scene for you in Cinema 4D,although I am just starting
    to learn it...give me some time and i will try it.(It might take a while so you might consider the model instead.)

    But,I will offer to do the dust bluescreen shot,I have Ultimatte,you can send me the bluescreen footage and the other footage and I will gladly Composite it for you.
  20. malducin Jedi Master

    Member Since:
    Oct 23, 2001
    star 4
    Well I've lately seen it done shot against black as far as I remember. Just like getting smoke or steam from a blacvk stream. Hmmm, maybe you could use baby powder against black, and then color correct it.
  21. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    Hummm, maybe this shot is too complicated after all.
  22. DarthFoole Jedi Master

    Member Since:
    Mar 23, 2001
    star 2
    no dude, bluescreening dust isn't a great idea because the trees won't occlude it correctly. it will look fine if you just mount a bunch of flocked twigs to a big board with a sheet of foam on it. hell, what you can do is set up a bunch of bare twigs on the board and then spray glue all over them and sprinkle on the flock. instant forest.

    try this before you make up your mind. get a piece of plywood, put a natty blanket or old sweatshirt on it, folded so it's 1-2 inches thick. put a layer of dirt on it, and throw a rock down on it. see how much dirt comes up.

    If you keep moaning about complicated, I'll do a damn test myself and upload it. hehehe.

    actually, put a bluescreen behind the crash site so you can matte in a shot of a larger forest behind the crash site. then you can take the dust that flies higher with the shot when you finalize it.
  23. PadawanNick Force Ghost

    Member Since:
    Jun 6, 2001
    star 4
    This sounds like a really great project!

    For the dust, how about a nice little blast of compressed air, shot at the loose dirt from under the impact or from behind the Xwing at the moment of impact? Another possibility is to show the crash into the trees, but not the ground impact, or even have the ship hung up in the trees. Cut in a few in-cockpit shots of the ship crashing through the branches maybe.

    Actually, isn't your ship crashing into the snow? Baking powder makes great snow.

    Don't worry about keying anything in the crash itself. Layering in CG ground desbris should really enhance the shot, but you don't need any keying in the source video. Even if some of your CG work has to pass behind a "real" tree, how many frames is that really going to last? It shouldn't be too dificult to rotoscope a mask around any foreground objects.

    How tall are the trees planned to be in relation to the XWing?

    Most train scale trees are HO, or O gauge, which is very small compared to your average sized Xwing model. If you're making your trees tall enough, you could taper some balsa dowels and stain them to form the truncks of tall pine trees. They would also be rather brittle and you could help the snapping with a few well placed razor cuts.

    Litchen should be reasonablely convincing for the greenary. (Especially when you give it a good coating of snow, then layer in some of that really cool CG snow fall you've been showing us.)


    So, long story short:
    If you're up for building the model Xwing and trees, the shot should not be too complex. Go for it. You're in overcast, snowy weather. Shoot against a grey background, or even pick up a snowy mountain backdrop from a train store. You're raw shot will not look tremendously convincing, but this is where your CGI skills will shine. Layer in additional trees, dust, snow smoke, all CG. You'll do great! Keep thinking of those Pearl harbor before and after shots!!!!!

    And one more thing...

    Have fun!
  24. Iyidin_Kyeimo Jedi Knight

    Member Since:
    Sep 21, 2000
    star 3
    I'd say do as much as you can in the computer. i.e. forget the dust. Just have a small corpse of trees, surrounded by bluescreen. Keep the angle tight in on the X-wing to minimise the background you'll have to fill in. Cut the model up as you want it to break. Film the crash and then add the dust, debris and background in the computer where you are far more confident.
  25. PixelMagic Force Ghost

    Member Since:
    Oct 8, 2001
    star 5
    I suck at bluescreening. And it would be ENORMOUSLY difficult to key out thinking like branches and leaves. SO, that means all effects have to be done in-camera. It really doesn't need a background, seeing as how the background can just be the sky. And I haven't completely abandoned the project, because I'm going to pick up the X-wing model today. :)


    EDIT: Hummm, It's not looking too good. I can't find the X-Wing model anywhere.
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